static ulong TraverseSlope(List <string> pattern, Slope slope)
{
var treesEncountered = 0UL;
var patternLengthRight = pattern[0].Count();
var bottomOfSlope = pattern.Count();
var currentRow = 0;
var currentColumn = 0;
while (currentRow <= bottomOfSlope)
{
currentColumn += slope.Right;
currentRow += slope.Down;
var patternColumn = currentColumn - (patternLengthRight * (currentColumn / patternLengthRight));
if (currentRow < bottomOfSlope && pattern[currentRow][patternColumn] == '#')
{
treesEncountered++;
}
}
Console.WriteLine($@"We would encounter {treesEncountered} trees on a slope of (Down {slope.Down}, Right {slope.Right}).");
return(treesEncountered);
}
static Func <string, int, bool> TreeDetectorFactory(Slope currentTrajectory)
{
return((x, index) =>
{
if ((index + 1) % currentTrajectory.Down == 0)
{
return x[(index * currentTrajectory.Right) % x.Length] == '#';
}
return false;
});
}
static ulong TraverseSlopeWithMap(List <string> pattern, Slope slope)
{
var treesEncountered = 0UL;
var patternLengthRight = pattern[0].Count();
var patternLengthDown = pattern.Count();
var repeatPatternRight = slope.Right * (patternLengthDown / slope.Down);
var repeatPatternDown = 1;
var totalColumns = patternLengthRight * repeatPatternRight;
var totalRows = patternLengthDown * repeatPatternDown;
var currentRow = 0;
var currentColumn = 0;
var map = new List <string>();
for (var i = 0; i < pattern.Count(); i++)
{
var row = string.Concat(Enumerable.Repeat(pattern[i], repeatPatternRight));
map.Add(row);
}
System.IO.File.WriteAllLines($@"map_{slope.Down}_{slope.Right}.txt", map);
var mapTraversed = map.ToList();
while (currentRow <= totalRows)
{
currentColumn += slope.Right;
currentRow += slope.Down;
if (currentRow < totalRows)
{
if (mapTraversed[currentRow][currentColumn] == '#')
{
mapTraversed[currentRow] = MarkMap(mapTraversed[currentRow], currentColumn, 'X');
treesEncountered++;
}
else
{
mapTraversed[currentRow] = MarkMap(mapTraversed[currentRow], currentColumn, 'O');
}
}
}
System.IO.File.WriteAllLines($@"maptraversed_{slope.Down}_{slope.Right}.txt", mapTraversed);
Console.WriteLine($@"We would encounter {treesEncountered} trees on a slope of (Down {slope.Down}, Right {slope.Right}).");
return(treesEncountered);
}